Handshaking Protocol for Distributed Implementation of Reo

Reo, an exogenous channel-based coordination language, is a model for service coordination wherein services communicate through connectors formed by joining binary communication channels. In order to establish transactional communication among services as prescribed by connector semantics, distributed ports exchange handshaking messages signalling which parties are ready to provide or consume data. In this paper, we present a formal implementation model for distributed Reo with communication delays and outline ideas for its proof of correctness. To reason about Reo implementation formally, we introduce Timed Action Constraint Automata (TACA) and explain how to compare TACA with existing automata-based semantics for Reo. We use TACA to describe handshaking behavior of Reo modeling primitives and argue that in any distributed circuit remote Reo nodes and channels exposing such behavior commit to perform transitions envisaged by the network semantics.Comment: In Proceedings FOCLASA 2014, arXiv:1502.0315

Treo: Textual Syntax for Reo Connectors

Reo is an interaction-centric model of concurrency for compositional specification of communication and coordination protocols. Formal verification tools exist to ensure correctness and compliance of protocols specified in Reo, which can readily be (re)used in different applications, or composed into more complex protocols. Recent benchmarks show that compiling such high-level Reo specifications produces executable code that can compete with or even beat the performance of hand-crafted programs written in languages such as C or Java using conventional concurrency constructs. The original declarative graphical syntax of Reo does not support intuitive constructs for parameter passing, iteration, recursion, or conditional specification. This shortcoming hinders Reo's uptake in large-scale practical applications. Although a number of Reo-inspired syntax alternatives have appeared in the past, none of them follows the primary design principles of Reo: a) declarative specification; b) all channel types and their sorts are user-defined; and c) channels compose via shared nodes. In this paper, we offer a textual syntax for Reo that respects these principles and supports flexible parameter passing, iteration, recursion, and conditional specification. In on-going work, we use this textual syntax to compile Reo into target languages such as Java, Promela, and Maude.Comment: In Proceedings MeTRiD 2018, arXiv:1806.0933

A Compositional Semantics for Stochastic Reo Connectors

In this paper we present a compositional semantics for the channel-based coordination language Reo which enables the analysis of quality of service (QoS) properties of service compositions. For this purpose, we annotate Reo channels with stochastic delay rates and explicitly model data-arrival rates at the boundary of a connector, to capture its interaction with the services that comprise its environment. We propose Stochastic Reo automata as an extension of Reo automata, in order to compositionally derive a QoS-aware semantics for Reo. We further present a translation of Stochastic Reo automata to Continuous-Time Markov Chains (CTMCs). This translation enables us to use third-party CTMC verification tools to do an end-to-end performance analysis of service compositions.Comment: In Proceedings FOCLASA 2010, arXiv:1007.499

Transitioning from kōhanga reo to kura

This is a collaborative cross-sector research project involving a kōhanga reo (Māori immersion early childhood language nest) kura (Māori language immersion school) and university-based researchers. It focuses on tamariki (children) moving from kōhanga reo to kura classrooms and will examine the development of an 'akoranga whakawhiti', a transition programme that will be based at Te Kōhanga Reo o Ngā Kuaka in Hamilton. The over arching research question for this project is: Pēhea rā te āhuatanga me te kounga o ngā whakawhitinga mai i te kōhanga ki te kura mō ngā tamariki, whānau, kaiako me te hāpori? - What do effective transitions from kōhanga reo to kura look like, feel like, and sound like, for tamariki, whānau, kaiako and the community? The project aims to provide important new insights into learning and teaching in Māori-medium settings and into ways of enhancing transitions from Maori-medium early childhood education to Māori medium classrooms

Nonprofit Strategies for 1- to 4-Unit REO Properties: An Analytical Framework

Real estate owned (REO) housing resulting from the recent foreclosure crisis threatens to destabilize low- and moderate-income neighborhoods across the country. Nonprofit organiza-tions seeking to redevelop these properties into affordable housing face weak market condi-tions and operate with limited resources and capacity. This study presents a framework through which nonprofits can analyze REO redevelopment opportunities for 1- to 4-unit properties within their communities. The paper specifies the conditions necessary for REO redevelopment and discusses how local market conditions, the geographic distribution and the physical characteristics of REOs, their ownership and legal status, internal organizational capacity, and public policies each affect nonprofit efforts to acquire, rehabilitate, sell and rent REO properties. Finally, this paper considers the unique difficulties of the current situation relative to past vacant-housing scenarios and concludes that many nonprofits may wish to pursue alternative, non-redevelopment strategies

A Procedure for Splitting Processes and its Application to Coordination

We present a procedure for splitting processes in a process algebra with multi-actions (a subset of the specification language mCRL2). This splitting procedure cuts a process into two processes along a set of actions A: roughly, one of these processes contains no actions from A, while the other process contains only actions from A. We state and prove a theorem asserting that the parallel composition of these two processes equals the original process under appropriate synchronization. We apply our splitting procedure to the process algebraic semantics of the coordination language Reo: using this procedure and its related theorem, we formally establish the soundness of splitting Reo connectors along the boundaries of their (a)synchronous regions in implementations of Reo. Such splitting can significantly improve the performance of connectors.Comment: In Proceedings FOCLASA 2012, arXiv:1208.432

Silicone elastomers filled with rare earth oxides

Silicones which possess, amongst others, remarkable mechanical properties, thermal stability over a wide range of temperatures and processability, and rare earth oxides(REO), known for their unique optic, magnetic and catalytic properties can be coupled into multifunctional composite materials(SREOs). In addition, the intrinsic hydrophobicity of REO and polysiloxanes makes them easily compatible without the need for surface treatments of the former. Thus, europium oxide (Eu2O3), gadolinium oxide (Gd2O3) and dysprosium oxide (Dy2O3)in amounts of 20 pph are incorporated as fillers into silicone matrices, followed by processing mixture as thin films and crosslinking at room temperature. The analysis of the obtained films reveals the changes induced by these fillers in the thermal, mechanical, dielectric and optical properties, as well as the hydrophobicity of the silicones. The luminescence properties of S-REO composites were investigated by fluorescence spectra and lifetime - resolved measurements with a multiemission peaks from blue to greenish register. The thermogravimetrical analysis indicates an increasing of thermal stability of the composites that contain REO, compared to pure silicone. As expected, the dielectric permittivity significantly increased due to nature of the fillers, while the dielectric loss values are relatively low for all samples, indicating a minimal conversion of electrical energy in the form of heat within bulk composites. The presence of rare earth oxides into the silicone matrix facilitates the motions of long-range charge carriers through the network resulting in higher values of conductivity of the composite films. The stress-strain measurements revealed the reinforcing effect of the rare earth metal oxides on a silicone matrix, leading to a significant increase of Young modulus. The known hydrophobicity of silicones is further enhanced by the presence of REO

Laboratory and greenhouse assessment of plant availability of organic N in animal manure

Laboratory data (thermal fractionation, pepsin extraction, C:No ratio) of dung and manure were mutually compared and contrasted with plant-availability of organic N (No) as found in a greenhouse experiment according to the double-pot technique. Two types of fresh cow dung (one with a relatively wide and the other with a relatively narrow C:No ratio) and four types of manure (from poultry, sheep, pigs and cow) were compared with ammonium nitrate as chemical reference fertilizer. Relative effectiveness of organic N (REo) was used as characteristic; it was calculated as the fraction of organic N that has the same availability to plants as inorganic N. REo for poultry and sheep manure could not be assessed, probably because of NH3 volatilization causing direct damage to plants and N losses. REo values decreased in the order: dung with narrow C:No > dung with wide C:No > pig manure > cow manure. Thermal fractionation did not provide a suitable index of plant-availability of organic N. Pepsin extracted organic N gave a positive, and C:No ratio a negative relationship with REo. Also between pepsin extracted organic N and C:No ratio a negative relationship was found. As C:No ratio is relatively easy to determine, it is considered the most practical laboratory index for plant availability of organic N in animal manures low in ammonia. When using the double-pot technique, application rates of manure types high in ammonia should be restricte

Stories with happy endings: Preventing pet dog attacks on children

A number of dog safety resources have been produced as a result of this research. Obtain a copy of the children’s leaflet (about 5-6yrs) in English from https://hdl.handle.net/10289/968. Obtain a copy of the children’s leaflet (about 5-6yrs) in Te Reo Maori from https://hdl.handle.net/10289/975. Obtain a copy of the children’s booklet (about 8-9yrs) in English from https://hdl.handle.net/10289/930. Obtain a copy of the children’s booklet (about 8-9yrs) in Te Reo Maori from https://hdl.handle.net/10289/984. Obtain a copy of the parents’/caregivers’ booklet in English from https://hdl.handle.net/10289/931. The Te Reo Maori version of the parents’/caregivers’ booklet will be available in 2009.This 2007-8 CAPFNZ Summer Research Scholarship had as its objective the identification of valid and reliable guidelines for safe interaction between children and pet dogs in their homes or known to them and their incorporation in a range of age-appropriate educational resources